1 Answer
ISSUE:
If DTC 67 (Air injection operation) is flagged on the Vehicle Condition Monitor, PDU will not
recognize or erase the code.
ACTION:
If DTC 67 is indicated on the VCM of XJS V12 or XJ12 vehicles, check for normal operation of
the Secondary Air Injection System (AIR).
Secondary Air Injection System Check:
Start engine.
NOTE: At engine start-up with coolant temperature below 1170 F (470 C), the Secondary
Air Injection Pump (AIRP) operates continuously until the coolant
temperature reaches 1170 F (470 C).
• Coolant temperature above 1170 F (470 C).
At engine start-up with coolant temperature above 1170 F (470 C), the AIRP operates for a
programmed period of time depending on coolant temperature. The AIRP then operates a
second time for OBD monitoring.
NOTE: If engine speed exceeds 900 RPM during the OBD monitoring phase, the
AIRP switches off. When the engine returns to normal idle speed OBD
monitoring will repeat and the AIRP will operate.
If Oxygen Sensor Feedback (HO2 SFB) indicates excess oxygen (lean) in the exhaust while
the AIRP is running the second time (OBD monitoring), the OBD test is passed.
If Oxygen Sensor Feedback (HO2 SFB) does not indicate excess oxygen (lean) while the
AIRP is running the second time (OBD monitoring), the CHECK ENGINE light turns on and
DTC 67 is flagged.
Refer to Service Manual section 17.3 for DTC 67 diagnosis information.
To erase the DTC from ECM memory:
• Switch ignition OFF.
• Disconnect and reconnect the fuel injection ECM.
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